930 CARDUACEAE 



elliptic, 1-2 dm. long, those of the stem-leaves oblanceolate; heads solitary; invo- 

 lucre 2-2.5 cm. high, 5-6 cm. broad; bracts numerous, linear-lanceolate, acute 

 or acuminate, hirsute-ciliate on the margins and back; ligules 2-4 cm. long; pappus 

 coroniform or cleft into several teeth. Hills: Mont. n Wyo. Ore. Wash. 

 Submont. My-Jl. 



2. W. amplexicaulis Nutt. Stem 3-6 dm. high, glabrous; basal leaves 

 petioled, 3-4 dm. long; blades oblong, elliptic or lanceolate, denticulate or entire, 

 glossy, reticulate, glabrous; upper stem-leaves lanceolate or ovate, sessile or 

 somewhat clasping; involucres 2 cm. high, 2-4 cm. wide; bracts rather few, 

 broadly lanceolate, acute, glabrous, firm; ligules 3-4 cm. long; pappus coroni- 

 form, but cleft into distinct teeth. Moist valleys: Mont. Colo. Utah Ore. 

 B.C. Submont. Mont. My-Au. 



3. W. robusta Nutt. Stem decumbent at the base, 3-4 dm. high, sparingly 

 hirsute; basal leaves 2-3 dm. long, short-petioled; blades oblanceolate, acute, 

 sparingly hirsutulous or scabrous; stem-leaves lanceolate and sessile; involucres 

 1.5-2 cm. high, 3-4 cm. broad; bracts lanceolate, hirsute-ciliate on the margins 

 and back; ligules 3-4 cm. long; pappus of a toothed crown and 1-4 stout awns. 

 VaUeys: Wash. Ida. Calif. Son. My-Jl. 



4. W. arizonica A. Gray. Stem 3-5 dm. high, rather copiously hirsute- 

 villous; basal leaves 2-4 dm. long, petioled; blades oblanceolate or oblong-ob- 

 lanceolate, densely pubescent; upper stem-leaves sessile, ovate or lanceolate; 

 involucres about 2 cm. high, 3-4 cm. wide; bracts oblong-lanceolate, acute, hir- 

 sute and finely puberulent; ligules 3-5 cm. long; crown of pappus with teeth, 

 and 1 or 2 awns. Mountains, along streams: N.M. Colo. Utah Ariz. Sub- 

 mont. My-Au. 



5. W. scabra Hook. Stem leafy, hispidulous-scabrous, soon turning straw- 

 colored or white; leaves linear, very scabrous, 5-8 cm. long, 6-12 mm. wide; 

 involucres about 2 cm. high and 3 cm. broad; bracts linear-subulate, attenuate, 

 hispid-ciliate and hirsute; ligules 2.5-4 cm. long; pappus of 3-4 blunt teeth. Dry 

 plains: Wyo. N.M. Utah. Son. Submont. Je-S. 



73. HELIANTHUS L. SUN-FLOWER, GROUND ARTICHOKE. 



Erect, mostly branched annuals or perennials, with simple leaves and large, 

 peduncled, corymbose or solitary heads. Involucre hemispherical or depressed; 

 its bracts imbricated in several series. Receptacle flat or convex, rarely conic, 

 with paleae subtending the disk-flowers. Ray-flowers neutral; ligules yellow, 

 spreading, mostly entire. Disk-flowers perfect, fertile; their corollas tubular, 

 yellow, brown or purple. Anthers entire or minutely 2-toothed at the base. 

 Style-branches with hirsute appendages. Achenes more or less 4-angled and 

 somewhat compressed. Pappus of 2 scales or awns, sometimes with a few addi- 

 tional smaller intermediate ones, deciduous. 



Annuals; leaves broad, ovate or cordate or lanceolate; disk purple or dark brown. 

 Bracts ciliate, hispid, ovate or obovate, abruptly acuminate. 



Lower leaves at least ovate or cordate, distinctly toothed. 1. H. lenticularis. 

 Leaves lanceolate or narrowly deltoid, minutely toothed or entire. 



2. H. aridus. 



Bracts not ciliate, canescent-strigose, lanceolate. 3. H. petiolaris. 



Perennials. 



Disk dark brown or purple. 



Leaves linear. 4. H. orgyalis. 



Leaves rhombic-ovate. 5. H. subrhomboideus. 



Disk yellow or light brownish. 



Bracts broadly lanceolate, acute, appressed. 6. H. pumilus. 



Bracts narrowly lanceolate, acuminate, more or less spreading or squarrose. 

 Leaves ovate. 7. H. tuberosus. 



Leaves lanceolate. 



Leaves rounded or obtuse at the base, subsessile. 8. H. divaricatus. 

 Leaves tapering at the base, petioled. 



Stem more or less scabrous or hispid; upper leaves subsessile. 



Leaves and stem very scabrous. 9. H. Maximiliani. 



Leaves scabrous above, hirsute beneath; stem more or less hirsute. 

 Upper leaves mostly alternate and indistinctly triple-nerved. 



10. H. giganteus. 



